This invention relates to a basting stitch mechanism in a zigzag sewing machine wherein the needle bar is driven in endwise reciprocation through a latch mechanism affixed to the needle bar.
The prior art discloses in the U.S. Pat. No. 3,559,602 a basting stich mechanism in a zigzag sewing machine in which the needle bar is driven in endwise reciprocation through a latch connection to the sewing machine driving means. The latch connection is disabled by urging the needle bar to a lateral position beyond the sewing range by a suitably contoured cam.
In the U.S. Pat. No. 3,782,311, a modular needle bar gate arrangement was utilized with the above principle in which the latch was disabled by relative movement between the needle bar and the gate supporting the needle bar. The jogging motion beyond the normal range of jogging motion required to disable the latch was again derived from a suitably contoured cam.
With the advent of the electronically controlled sewing machine, jogging motion of the needle bar gate was effected by utilization of a linear motor, as is disclosed in the U.S. Pat. No. 3,984,745. At that time, in order to make the operation of the basting stitch device compatible with the electronic control devices, the latch disabling was accomplished by the use of a solenoid. A solenoid baste switch disabling mechanism is first disclosed in U.S. Pat. No. 3,847,100, and later in the U.S. Pat. No. 3,872,809. However, the solenoid actuated basting devices involve the use of a considerable number of additional parts and the solenoid itself, resulting in greatly increased costs. What is required is some means of implementing basting in an electronically controlled sewing machine at a minimum cost without the necessity for costly components.